title: Quantifying uncertainty in measurement of mercury in suspended particulate matter by cold vapor technique using atomic absorption spectrometry with hydride generator.
abstract: As a result of rapid industrialization several chemical forms of organic and inorganic mercury are constantly introduced to the environment and affect humans and animals directly. All forms of mercury have toxic effects; therefore accurate measurement of mercury is of prime importance especially in suspended particulate matter (SPM) collected through high volume sampler (HVS). In the quantification of mercury in SPM samples several steps are involved from sampling to final result. The quality, reliability and confidence level of the analyzed data depends upon the measurement uncertainty of the whole process. Evaluation of measurement uncertainty of results is one of the requirements of the standard ISO/IEC 17025:2005 (European Standard EN IS/ISO/IEC 17025:2005, issue1:1-28, 2006). In the presented study the uncertainty estimation in mercury determination in suspended particulate matter (SPM) has been carried out using cold vapor Atomic Absorption Spectrometer-Hydride Generator (AAS-HG) technique followed by wet chemical digestion process. For the calculation of uncertainty, we have considered many general potential sources of uncertainty. After the analysis of data of seven diverse sites of Delhi, it has been concluded that the mercury concentration varies from 1.59 ± 0.37 to 14.5 ± 2.9 ng/m(3) with 95% confidence level (k = 2).
authors.affiliation: CSIR-National Physical Laboratory, Dr K.S. Krishnan Marg, New Delhi, 110012 India.
authors.forename: Nahar
authors.initials: N
authors.lastname: Singh
authors.forename: Tarushee
authors.initials: T
authors.lastname: Ahuja
authors.forename: Vijay Narain
authors.initials: VN
authors.lastname: Ojha
authors.forename: Daya
authors.initials: D
authors.lastname: Soni
authors.forename: S Swarupa
authors.initials: SS
authors.lastname: Tripathy
authors.forename: Ivo
authors.initials: I
authors.lastname: Leito
keywords: Atomic absorption spectrometer-hydride generator; High volume sampler; Mercury; Uncertainty evaluation